The Research Of Using Surface Enhanced Raman Spectroscopy On Human Blood Serum For Lung Cancer Screening And Detection

Raman spectroscopy is a well-established analytical technique based on the inelastic scattering of monochromatic light by the vibrating atoms constituting the sample.It is widely used in fields such as materials,food,medicine,chemistry and so on,especially on biology and medicine.Its advantages are that it is quick,accurate and usually non-invasive.This project uses Raman spectroscopy on biological and medical samples,especially human blood serum,in order to facilitate the development of cancer screening using Raman spectroscopy.The three topics discussed in this article are as follows:1.This project improved upon one of the methods of making silver based SERS substrates.Production conditions and setups of the substrates made by TiO2 photo-catalysis method are investigated,ranging from dip-coating to photo-catalysis setups,in order to improve enhancement performance.The final result is an improved method that uses 254 nm,filtered UV light and quartz slides with optimized production conditions.Resulting substrate is a more uniform substrate that is suitable for serum measurement;it can be used to detect 10-8M R6 G molecules,and the standard deviation for different regions on a substrate is 16.9%,while standard deviation for different substrates are 14.5%.In 15 days,the enhanced intensity is only reduced by 15%.The substrates produced are used for serum's SERS measurement.2.This project used substrates produced by methods in chapter two for serum measurement.Serum measurement was optimized by tackling two obstacles of serum measurement: photo-degradation and serum solution compositions.Laser conditions,off-focus distances,serum amounts and concentrations and solvents are the conditions optimized in this chapter.Off focus distance of 30?m and 33% serum concentration is used to overcome the two obstacles above.Clear,uniform,repeatable and clean serum spectra are obtained as a result,which can then be used for data process.The serum Raman spectra can be used for lung cancer screening and3.This project used the research of the previous two chapters,and performed measurement on 160 human blood serum samples for data process.Various baseline correction methods and data processing methods were used for the classification and identification between sera from healthy individuals and lung cancer patients.A 95% overall correct cross validationresult was achieved,by using second order derivative factorizatiom method with rubberband baseline correction.The classification result is not strongly correlated with cancer stage,which means this method could correctly identify early stage lung cancer patients.Overall,this project proposed a full set of methods that could be used in future screening of lung cancer.In the future,we want to combine this research with researches on other body fluids and human samples,to further improve the screening detection,and classification capabilities of lung cancer,in order to prepare for the method's clinical applications.